The mature barley seed proteome is dominated by proteins involved in stress responses, including the Pathogenesis-Related proteins (PRs). PRs are currently classified into 17 families. The biochemistry of the PRs families, whose members are constitutively present in barley seed, is surveyed in this paper. These proteins are assumed to protect dormant and germinating seeds against pathogenic microorganisms and pests. The current knowledge on PRs structural and functional properties is summarized in an attempt to illustrate their importance in barley seed innate resistance. At the same time, a platform to understand PRs technological function in cereal foods and in beverage processing and quality is provided.